The goal of this project is to determine the existence, nature and location of hepatic and gustatory afferent convergence in general visceral afferent structures of the brainstem and presumed ADH-releasing nuclei in the hypothalamus. The results of such a project may provide a basis of explanation for several phenomena related to ingestive behavior and may provide the evidence necessary for the firm neurophysiological establishment of direct hepatic afferent control over ADH release. The techniques to be applied to these studies include extracellular recordings of the activity of single neurons in combination with discrete infusion/superfusion solute stimulation of the liver and tongue and electrical stimulation of gustatory receptive fields and the hepatic vagus. In addition, spike-triggered averaging of responses from higher-order neurons correlated with lower order spike occurrence and antidromic pathway idenitification will be employed to achieve the goals set forth in this proposal.